Inbred corn line NPFF6228

ABSTRACT

Basically, this invention provides for an inbred corn line designated NPFF6228, methods for producing a corn plant by crossing plants of the inbred line NPFF6228, with plants of another corn plant. The invention relates to the various parts of inbred NPFF6228, including culturable cells. This invention also relates to methods for introducing transgenic transgenes into inbred corn line NPFF6228, and plants produced by said methods.

FIELD OF THE INVENTION

This invention is in the field of corn breeding. The invention relatesto a maize and it s seed designated NPFF6228, derivatives and hybridsthereof. This invention also is in the field of hybrid maize productionemploying the present inbred.

BACKGROUND OF THE INVENTION

Corn plants (Zea mays L.) can be self-pollinating or cross pollinating.Self pollination for extended time periods produces homozygousity atalmost all gene loci, forming a uniform population of true breedingprogeny. These are inbreds. Crossing two homozygous inbreds producesheterozygous gene loci in hybrid plants and seeds.

Maize plant breeding is a process to develop improved maize germplasm inan inbred or hybrid. Hybrids are developed with inbreds which aredeveloped by selecting corn lines and self pollinating these lines forseveral generations to develop homozygous pure inbred lines. Two inbredlines are crossed and hybrid seed is produced. One inbred is emasculatedand the pollen from the other inbred pollinates the emasculated inbred.The emasculated inbred, often referred to as the female, produces thehybrid seed F1. Emasculation of the inbred can be done by detasselingthe seed parent, or the inbred could have a male sterility factor whichwould eliminate the need to detassel the inbred.

Whether the seed producing plant is emasculated due to detasseling orCMS or transgenes, the seed produced by crossing two inbreds in thismanner is hybrid seed. This hybrid seed is F1 hybrid seed. The grainproduced by a plant grown from a F1 hybrid seed is referred to as F2 orgrain. Although, all F1 seed and plants, produced by this hybrid seedproduction system using the same two inbreds should be substantially thesame, all F2 grain produced from the F1 plant will be segregating maizematerial.

The hybrid seed production produces hybrid seed which is heterozygous.The heterozygosis results in hybrid plants, which are robust andvigorous plants. Inbreds on the other hand are mostly homozygous. Thishomozygosity renders the inbred lines less vigorous. Inbred seed can bedifficult to produce since the inbreeding process in corn linesdecreases the vigor. However, when two inbred lines are crossed, thehybrid plant evidences greatly increased vigor and seed yield comparedto open pollinated, segregating maize plants. An important consequenceof the homozygosity and the homogenity of the inbred maize lines is thatall hybrid seed produced from any cross of two such elite lines will bethe same hybrid seed and make the same hybrid plant. Thus the use ofinbreds makes hybrid seed which can be reproduced readily.

The ultimate objective of the commercial maize seed companies is toproduce high yielding, agronomically sound plants that perform well incertain regions or areas of the Corn Belt.

SUMMARY OF THE INVENTION

The present invention relates to an inbred corn line NPFF6228.Specifically, this invention relates to plants and seeds of this line.Additionally, this relates to a method of producing from this inbred,hybrid seed corn and hybrid plants with seeds from such hybrid seed.More particularly, this invention relates to the unique combination oftraits that combine in corn line NPFF6228.

Generally then, broadly the present invention includes an inbred cornseed designated NPFF6228. This seed produces a corn plant.

The invention also includes the tissue culture of regenerable cells ofNPFF6228, wherein the cells of the tissue culture regenerates plantscapable of expressing the genotype of NPFF6228. The tissue culture isselected from the group consisting of leaf, pollen, embryo, root, roottip, guard cell, ovule, seed, anther, silk, flower, kernel, ear, cob,husk and stalk, cell and protoplast thereof. The corn plant regeneratedfrom NPFF6228 or any part thereof is included in the present invention.The present invention includes regenerated corn plants that are capableof expressing NPFF6228's genotype, phenotype or mutants or variantsthereof.

The invention extends to hybrid seed produced by planting, inpollinating proximity which includes using preserved maize pollen asexplained in U.S. Pat. No. 5,596,838 to Greaves, seeds of corn inbredlines NPFF6228 and another inbred line if preserved pollen is not used;cultivating corn plants resulting from said planting; preventing pollenproduction by the plants of one of the inbred lines if two are employed;allowing cross pollination to occur between said inbred lines; andharvesting seeds produced on plants of the selected inbred. The hybridseed produced by hybrid combination of plants of inbred corn seeddesignated NPFF6228 and plants of another inbred line are a part of thepresent invention. This inventions scope covers hybrid plants and theplant parts including the grain and pollen grown from this hybrid seed.

The invention further includes a method of hybrid F1 production. A firstgeneration (F1) hybrid corn plant produced by the process of plantingseeds of corn inbred line NPFF6228; cultivating corn plants resultingfrom said planting; permitting pollen from another inbred line to crosspollinate inbred line NPFF6228; harvesting seeds produced on plants ofthe inbred; and growing a harvested seed are part of the method of thisinvention.

The present invention also encompasses a method of introducing at leastone targeted trait into maize inbred line comprising the steps of: (a)crossing plant grown from the present invention seed which is therecurrent parent, representative seed of which has been deposited, withthe donor plant of another maize line that comprises at least one targettrait selected from the group consisting of male sterility, herbicideresistance, insect resistance, disease resistance, amylose starch, andwaxy starch to produce F1 plants; (b) selecting from the F1 plants thathave at least one of the targeted traits, forming a pool of progenyplants with the targeted trait; (c) crossing the pool of progeny plantswith the present invention which is the recurrent parent to producebackcrossed progeny plants with the targeted trait; (d) selecting forbackcrossed progeny plants that have at least one of the target traitsand physiological and morphological characteristics of maize inbred lineof the recurrent parent, listed in Table 1 forming a pool of selectedbackcrossed progeny plants; and (e) crossing the selected backcrossedprogeny plants to the recurrent parent and selecting from the resultingplants for the targeted trait and physiological and morphologicalcharacteristics of maize inbred line of the recurrent parent, listed inTable 1 and reselecting from the pool of resulting plants and repeatingthe crossing to the recurrent parent and selecting step in succession toform a plant that comprises the desired trait and all of thephysiological and morphological characteristics of maize inbred line ofthe recurrent parent in the present invention listed in Table 1 asdetermined at the 5% significance level when grown in the sameenvironmental conditions.

This method and the following method of introducing traits can be donewith less back crossing events if the trait and/or the genotype of thepresent invention are selected for or identified through the use ofmarkers. SSR, microsatellites, SNP and the like decrease the amount ofbreeding time required to locate a line with the desired trait or traitsand the characteristics of the present invention. Backcrossing in two oreven three traits (for example the glyphosate, Europe corn borer, cornrootworm resistant genes) is routinely done with the use of markerassisted breeding techniques. This introduction of transgenes ormutations into a maize line is often called single gene conversion.Although, presently more than one gene particularly transgenes ormutations which are readily tracked with markers can be moved during thesame “single gene conversion” process, resulting in a line with theaddition of more targeted traits than just the one, but still having thecharacteristics of the present invention plus those characteristicsadded by the targeted traits.

The method of introducing a desired trait into maize inbred linecomprising: (a) crossing plant grown from the present invention seed,representative seed of which has been deposited the recurrent parent,with plant of another maize line that comprises at least one targettrait selected from the group consisting of nucleic acid encoding anenzyme selected from the group consisting of phytase, stearyl-ACPdesaturase, fructosyltransferase, levansucrase, amylase, invertase andstarch branching enzyme, the donor parent to produce F1 plants; (b)selecting for the targeted trait from the F1 plants, forming a pool ofprogeny plants; (c) crossing the progeny plants with the recurrentparent to produce backcrossed progeny plants; (d) selecting forbackcrossed progeny plants that have at least one of the target traitand physiological and morphological characteristics of maize inbred lineof the present invention as listed in Table 1 forming a pool ofbackcrossed progeny plants; and repeating a step of crossing the newpool with the recurrent parent and selecting for the targeted trait andthe recurrent parents characteristics until the selected plant isessentially the recurrent parent with the targeted trait or targetedtraits. This selection and crossing may take at least 4 backcrosses ifmarker assisted breeding is not employed.

The inbred line and seed of the present invention are employed to carrythe agronomic package into the hybrid. Additionally, the inbred line isoften carrying transgenes that are introduced in to the hybrid seed.

Likewise included is a first generation (F1) hybrid corn plant producedby the process of planting seeds of corn inbred line NPFF6228;cultivating corn plants resulting from said planting; permitting pollenfrom inbred line NPFF6228 to cross pollinate another inbred line;harvesting seeds produced on plants of the inbred; and growing a plantfrom such a harvested seed.

A number of different techniques exist which are designed to avoiddetasseling in maize hybrid production. Some examples are switchablemale sterility, lethal genes in the pollen or anther, inducible malesterility, male sterility genes with chemical restorers. There arenumerous patented means of improving upon the hybrid production system.Some examples include U.S. Pat. No. 6,025,546, which relates to the useof tapetum-specific promoters and the barnase gene to produce malesterility; U.S. Pat. No. 6,627,799 relates to modifying stamen cells toprovide male sterility. Therefore, one aspect of the current inventionconcerns the present invention comprising one or more gene(s) capable ofrestoring male fertility to male-sterile maize inbreds or hybrids and/orgenes or traits to produce male sterility in maize inbreds or hybrids.

The inbred corn line NPFF6228 and at least one transgenic gene adaptedto give NPFF6228 additional and/or altered phenotypic traits are withinthe scope of the invention. Such transgenes are usually associated withregulatory elements (promoters, enhancers, terminators and the like).Presently, transgenes provide the invention with traits such as insectresistance, herbicide resistance, disease resistance increased ordecreased starch or sugars or oils, increased or decreased life cycle orother altered trait.

The present invention includes inbred corn line NPFF6228 and at leastone transgenic gene adapted to give NPFF6228 modified starch traits.Furthermore this invention includes the inbred corn line NPFF6228 and atleast one mutant gene adapted to give modified starch, acid or oiltraits, i.e. amylase, waxy, amylose extender or amylose. The presentinvention includes the inbred corn line NPFF6228 and at least onetransgenic gene: bacillus thuringiensis, the bar or pat gene encodingPhosphinothricin acetyl Transferase, Gdha gene, GOX, VIP, EPSP synthasegene, low phytic acid producing gene, and zein. The inbred corn lineNPFF6228 and at least one transgenic gene useful as a selectable markeror a screenable marker is covered by the present invention.

A tissue culture of the regenerable cells of hybrid plants produced withuse of NPFF6228 genetic material is covered by this invention. A tissueculture of the regenerable cells of the corn plant produced by themethod described above is also included.

DEFINITIONS

In the description and examples, which follow, a number of terms areused. In order to provide a clear and consistent understanding of thespecifications and claims, including the scope to be given such terms,the following definitions are provided.

ALLELE—Any alternative forms of sequence. Diploid cells carry twoalleles of the genetic sequence. These two sequence alleles correspondto the same locus (i.e. position) on homologous chromosomes.

ELITE INBRED—Maize plant that is substantially homozygous and whichcontributes useful agronomic and/or phenotypic qualities when used toproduce hybrids that are commercially acceptable.

GENE SILENCING—The loss or inhibition of the expression of a gene.

GENOTYPE—genetic makeup.

LINKAGE—Refers to a tendency of a segment of DNA on the same chromosometo not separate during meiosis of homologous chromosomes. Thus duringmeiosis this segment of DNA remains unbroken more often than expected bychance.

LINKAGE DISEQUILIBRIUM—Alleles tendency to remain in linked groups whensegregating from parents to progeny, than expected from chance.

LOCUS—A defined segment of DNA. This segment is often associated with anallele position on a chromosome.

PHENOTYPE—The detectible characteristics of the maize plant. Thesecharacteristics often are detections of the genotype/environmentinteraction.

PLANT—this includes reference to an immature or mature whole plant,including a plant that has been detasseled or from which seed or grainhas been removed. Seed or embryo that will produce the plant is alsoconsidered to be the plant.

Early Season Trait Codes

Emergence Rating (EMRGR): Recorded when 50% of the plots in the trialare at V1 (1 leaf collar) growth stage.

-   -   1=All plants have emerged and are uniform in size    -   3=All plants have emerged but are not completely uniform    -   5=Most plants have emerged with some just beginning to break the        soil surface, noticeable lack of uniformity    -   7=Less than 50% of the plants have emerged, and lack of        uniformity is very noticeable    -   9=A few plants have emerged but most remain under the soil        surface.        Seedling Growth (SVGRR or Vigor): Recorded between V3 and V5        (3-5 leaf stage) giving greatest weight to seedling plant size        and secondary weight to uniform growth.    -   1=Large plant size and uniform growth    -   3=Acceptable plant size and uniform growth    -   5=Acceptable plant size and might be a little non-uniform    -   7=Weak looking plants and non-uniform growth    -   9=Small plants with poor uniformity        Purpling (PRPLR): Emergence and/or early growth rating. Purpling        is more pronounced on the under sides of leaf blades especially        on midribs.    -   1=No plants showing purple color    -   3=30% plants showing purple color    -   5=50% plants showing purple color    -   7=70% plants showing purple color    -   9=90+% plants showing purple color        Herbicide Injury (HRBDR) List the herbicide type, which is being        rated. Then rated each hybrid/variety injury as indicated below.    -   1=No apparent reduction in biomass or other injury symptoms    -   5=Moderate reduction in biomass with some signs of sensitivity    -   9=Severe reduction in biomass with some mortality        Mid-Season Traits Codes        Heat Units to 50% Silk (HUPSN): Recorded the day when 50% of all        plants within a plot show 2 cm or more silk protruding from the        ear. Converted days to accumulated heat units from planting.        Heat units to 50% Pollen Shed (HUPSN): Recorded the day when 50%        of all plants within a plot are shedding pollen. Converted days        to accumulated heat units from planting.        Plant Height (PLHTN): After pollination, recorded average plant        height of each plot. Measured from ground to base of leaf noted.        Plant Ear Height (ERHTN): After pollination record average ear        height of each plot. Measure from ground to base of ear node        (shank).—for Inbreds        Plant Ear Height in CM: After pollination record average ear        height of each plot. Measure from ground to base of ear node        (shank).—for Hybrids        Root Lodging Early % (ERTLP): Early root lodging occurs up to        about two weeks after flowering and usually involves        goosenecking. The number of root lodged plants are counted and        converted to percentage.        Shed Duration (Shed Duration): Sum of daily heatunits for days        when plants in the plot are actively shedding pollen.        Foliar Disease (LFDSR): Foliar disease ratings taken one month        before harvest through harvest. The predominant disease should        be listed in the trial information and individual hybrid ratings        should be given.    -   1=No lesions to two lesions per leaf.    -   3=A few scattered lesions on the leaf. About five to ten percent        of the leaf surface is affected.    -   5=A moderate number of lesions are on the leaf. About 15 to 20        percent of the leaf surface is affected.    -   7=Abundant lesions are on the leaf. About 30 to 40 percent of        the leaf surface is affected.    -   9=Highly abundant lesions (>50 percent) on the leaf. Lesions are        highly coalesced. Plants may be prematurely killed.        Data collection (as described above) on the following diseases:

Common Rust (CR) Eye Spot (ES) Gray Leaf Spot (GLS) Northern Corn LeafBlight (NCLB) Stewart's Bacterial Wilt (SBW) Southern Corn Leaf Blight(SCLB) Southern Rust (SR) Corn Virus Complex (CVC)Maize response to diseases can also be rated as:

-   -   R=Resistant=1 to 2 rating    -   MR=Moderately Resistant=3 to 4 rating    -   MS=Moderately Susceptible=5 to 6 rating    -   S=Susceptible=7 to 9 rating        Preharvest Trait Codes        Heat units to Black Layer (HUBLN): The day when 50% of all        plants within a plot reach black layer stage is recorded.        Convert days to accumulated heat units from planting.        Harvest Population (HAVPN): The number of plants in yield rows,        excluding tillers, in each plot are counted.        Barren Plants (BRRNP): The number of plants in yield rows having        no ears and/or abnormal ears with less than 50 kernels are        counted.        Dropped Ears (DROPP): The numbers of ears lying on the ground in        yield rows are counted.        Stalk Lodging % (STKLP): Stalk lodging will be reported as        number of plants broken below the ear without pushing, excluding        green snapped plants. The number of broken plants in yield rows        are counted and converted to percent.        Root Lodging Late % (LRTLP): Late root lodging can usually start        to occur about two weeks after flowering and involves lodging at        the base of the plant. Plants leaning at a 30-degree angle or        more from the vertical are considered lodged. The number of root        lodged plants in yield rows are counted and converted to        percent.        Push Test for Stalk and Root Quality on Erect Plants % (PSTSP or        PCT Push or % Pushtest): The push test is applied to trials with        approximately five percent or less average stalk lodging. Plants        are pushed that are not root lodged or broken prior to the push        test. Standing next to the plant, the hand is placed at the top        ear and pushed to arm's length. Push one of the border rows        (four-row small plot) into an adjacent plot border row. The        number of plants leaning at a 30-degree angle or more from the        vertical, including plants with broken stalks prior to pushing        are counted. Plants that have strong rinds that snap rather than        bend over easily are not counted. The goal of the push test is        to identify stalk rot and stalk lodging potential, NOT ECB        injury.        PUSXN: Push ten plants and enter the number of plants that do        not remain upright.        Intactness (INTLR):    -   1=Healthy appearance, tops unbroken    -   5=25% of tops broken    -   9=majority of tops broken        Plant Appearance (PLTAR): This is a visual rating based on        general plant appearance taking into account all factors of        intactness, pest, and disease pressure.    -   1=Complete plant with healthy appearance    -   5=plants look OK    -   9=Plants not acceptable        Green Snap (GRSNP or PCTGS or % GreenSnap): Counted the number        of plants in yield rows that snapped below the ear due to        brittleness associated with high winds.        Stay-green (STGRP): This is an assessment of the ability of a        grain hybrid to retain green color as maturity approaches (taken        near the time of black-layer) and should not be a reflection of        hybrid maturity or leaf disease. Recorded % of green tissue.        This may be listed as a Stay Green Rating instead of a        Percentage.        Stay Green Rating (STGRR): This is an assessment of the ability        of a grain hybrid to retain green color as maturity approached        (taken near the time of black layer or if major differences are        noted later). This rating should not be a reflection of the        hybrid maturity or leaf disease.    -   1=solid Green Plant    -   9=no green tissue        Ear/Kernel Rots (KRDSR): If ear or kernel rots are present, husk        ten consecutive ears in each plot and count the number that have        evidence of ear or kernel rots, multiply by 10, and round up to        the nearest rating as described below. Identify and record the        disease primarily responsible for the rot.    -   1=No rots, 0% of the ears infected.    -   3=Up to 10% of the ears infected.    -   5=11 to 20% of the ears infected.    -   7=21 to 35% of the ears infected.    -   9=36% or more of the ears infected.        Grain Quality (GRQUR): Taken on husked ears after black layer        stage. The kernel cap integrity and relative amount of soft        starch endosperm along the sides of kernels is rated.    -   1=smooth kernel caps and or 10% or less soft starch    -   3=slight kernel wrinkles and or 30% soft starch    -   7=moderate kernel wrinkles and or 70% soft starch    -   9=severe kernel wrinkled and or 90% or more soft starch        Preharvest Hybrid Characteristics        Ear Shape (DESHR): Slender, Semi-Blocky, Blocky    -   1=Blocky    -   5=Semi-blocky    -   9=Slender        Ear Type (EARFR): Fixed, Semi-Fixed, Flex    -   1=Flex    -   5=Semi-flex    -   9=Fixed        Husk Cover (HSKCR): Short, Medium, Long    -   1=Long    -   5=Medium    -   9=Short        Kernel Depth (KRLNR): Shallow, Medium, Deep    -   1=Deep    -   5=Medium    -   9=Short (shallow)        Shank Length (SHLNR): Short, Medium, Long    -   1=Short    -   5=Medium    -   9=Long        Kernel Row Number (KRRWN): The average number of kernel rows on        3 ears.        Cob diameter (COBDR): Cob diameter is to be taken with template.    -   1: small    -   5: Medium    -   9: Large        Harvest Trait Codes        Number of Rows Harvested (NRHAN)        Plot Width (RWIDN)        Plot Length (RLENN)        Yield Lb/Plot (YGSMN): bushels per acre adjusted to 15.5%        moisture        Test Weight (TSTWN or TWT): test weight at harvest in pounds per        bushel        Moisture % (MST_P): percent moisture or grain at harvest        Adjusted Yield in Bu/A (YBUAN)        Color Codes        Kernel Type: (KRTPN)    -   1) Dent    -   2) Flint        Endosperm Type: (KRTEN)    -   1) normal    -   2) amylose    -   3) waxy    -   4) other        Sterile Type (MSCT):    -   1) no    -   if yes cytoplasm type then:    -   2) c-type    -   3) s-type        Anthocyanin of Brace Roots (PBRCC): the presence of color on 60%        of the brace roots during pollen shed.    -   1) Absent    -   2) Faint    -   3) Moderate    -   4) Dark    -   5) Brace Roots not present    -   6) Green    -   7) Red    -   8) Purple        Anther Color (ANTCC): at 50 percent pollen shed observe the        color of newly extruded anthers, pollen not yet shed    -   1) Yellow    -   2) Red    -   3) Pink    -   4) Purple        Glume Color (GLMCC): color of glumes prior to pollen shed    -   1) Red    -   2) Green        Silk Color (SLKCC): Taken at a late flowering stage when all        plants have fully extruded silk. Silks at least 2″ long but        still fresh.    -   1) Yellow    -   2) Pink    -   3) Red        Kernel Color (KERCC): the main color of the kernel from at least        three ears per ear family.    -   1) Yellow    -   2) White        Cob Color (COBCC): the main color of the cob after shelling from        at least three ears per ear family.    -   1) Red    -   2) Pink    -   3) White

Input ABR. Description Value EMRGN Final number of plants per plot #REGNN Region Developed: 1. Northwest # 2. Northcentral 3. Northeast 4.Southeast 5. Southcentral 6. Southwest 7. Other CRTYN Cross type: 1. sc2. dc 3. 3w 4. msc 5. m3w # 6. inbred 7. rel. line 8. other KRTPN Kerneltype: 1. sweet 2. dent 3. flint 4. flour # 5. pop 6. ornamental 7.pipecorn 8. other EMERN Days to Emergence EMERN # Days ERTLP % Rootlodging: (before anthesis): #% GRSNP % Brittle snapping: (beforeanthesis): #% TBANN Tassel branch angle of 2nd primary lateral degreebranch at anthesis: HUPSN Heat units to 50% pollen shed: (fromemergence) # HU SLKCN Silk color: #/Munsell value HU5SN Heat units to50% silk: (from emergence) # HU DSAZN Days to 50% silk in adapted zone:# Days HU9PN Heat units to 90% pollen shed: (from emergence) # HU HU19NHeat units from 10% to 90% pollen shed: # HU DA19N Days from 10% to 90%pollen shed: # Days LSPUR Leaf sheath pubescence of second leaf above #the ear (at anthesis) 1-9 (1 = none): ANGBN Angle between stalk and 2ndleaf above the ear degree (at anthesis): CR2LN Color of 2nd leaf abovethe ear (at anthesis): #/Munsell value GLCRN Glume Color: #/Munsellvalue GLCBN Glume color bars perpendicular to their veins # (glumebands): 1. absent 2. present ANTCN Anther color: #/Munsell value PLQURPollen Shed: 1-9 (0 = male sterile) # HU1PN Heat units to 10% pollenshed: (from emergence) # HU LAERN Number of leaves above the top earnode: # LTBRN Number of lateral tassel branches that originate # fromthe central spike: EARPN Number of ears per stalk: # APBRR Anthocyaninpigment of brace roots: 1. absent # 2. faint 3. moderate 4. dark TILLNNumber of tillers: # HSKCN Husk color 25 days after 50% silk: (fresh)#/Munsell value MLWVR Leaf marginal waves: 1-9 (1 = none) # LFLCR Leaflongitudinal creases: 1-9 (1 = none) # ERLLN Length of ear leaf at thetop ear node: # cm ERLWN Width of ear leaf at the top ear node at the #cm widest point: PLHTN Plant height to tassel tip: # cm ERHCN Plantheight to the top ear node: # cm LTEIN Length of the internode betweenthe ear node # cm and the node above: LTASN Length of the tassel fromtop leaf collar to tassel # cm tip: HSKDN Husk color 65 days after 50%silk: (dry) #/Munsell value DSGMN Days from 50% silk to 25% grainmoisture in # Days adapted zone: SHLNN Shank length: # cm ERLNN Earlength: # cm ERDIN Diameter of the ear at the midpoint: # mm EWGTNWeight of a husked ear: # gm KRRWR Kernel rows: l. indistinct 2.distinct # KRNAR Kernel row alignment: 1. straight # 2. slightly curved3. curved ETAPR Ear taper: 1. slight 2. average 3. extreme # KRRWNNumber of kernel rows: # COBCN Cob color: #/Munsell value HSKTR Husktightness 65 days after 50% silk: 1-9 # (1 = loose) COBDN Diameter ofthe cob at the midpoint: # mm YBUAN Yield: # kg/ha KRTEN Endospermtype: 1. sweet 2. extra sweet 3 3. normal 4. high amylose 5. waxy 6.high protein 7. high lysine 8. super sweet 9. high oil 10. other KRCLNHard endosperm color: #/Munsell value ALECN Aleurone color: #/Munsellvalue ALCPR Aleurone color pattern: 1. homozygous # 2. segregating KRLNNKernal length: # mm KRWDN Kernel width: # mm KRDPN Kernel thickness: #mm K1KHN 100 kernel weight: # gm HSKCR Husk extension: 1. short (earexposed) 2. medium # (8 cm) 3. long (8-10 cm) 4. very long (>10 cm)KRPRN % round kernels on 13/64 slotted screen: #% HEPSR Position of ear65 days after 50% silk: 1. upright # 2. horizontal 3. pendent STGRPStaygreen 65 days after anthesis: 1-9 (1 = worst) # DPOPP % dropped ears65 days after anthesis: % LRTRP % root lodging 65 days after anthesis: %HU25N Heat units to 25% grain moisture: (from # HU emergence) HUSGN Heatunits from 50% silk to 25% grain moisture in # HU adapted zone:

DETAILED DESCRIPTION OF THE INVENTION

The inbred provides uniformity and stability within the limits ofenvironmental influence for traits as described in the VarietyDescription Information (Table 1) that follows.

Male sterility and/or CMS systems for maize parallel the CMS typesystems that have been routinely used in hybrid production in sunflower.

To produce these types of hybrids, the companies must develop inbreds,which carry needed traits into the hybrid combination. Hybrids are notoften uniformly adapted for the entire Corn Belt, but most often arespecifically adapted for regions of the Corn Belt. Northern regions ofthe Corn Belt require shorter season hybrids than do southern regions ofthe Corn Belt. Hybrids that grow well in Colorado and Nebraska soils maynot flourish in richer Illinois and Iowa soils. Thus, a variety of majoragronomic traits is important in hybrid combination for the various CornBelt regions, and has an impact on hybrid performance.

Inbred line development and hybrid testing have been emphasized in thepast half-century in commercial maize production as a means to increasehybrid performance. Inbred development can be by pedigree selection,haploid/dihaploid production, and recurrent selection. Pedigreeselection can be the selection in an F2 population produced from aplanned cross of two genotypes (often elite inbred lines), or selectionof progeny of synthetic varieties, open pollinated, composite, orbackcrossed populations. This type of selection is effective for highlyinheritable traits, but other traits, for example, yield requiresreplicated test crosses at a variety of stages for accurate selection.

Maize breeders select for a variety of traits in inbreds that impacthybrid performance along with selecting for acceptable parental traits.Such traits include but are not limited to: yield potential in hybridcombination, dry down, maturity, grain moisture at harvest, greensnap,resistance to root lodging, resistance to stalk lodging, grain quality,disease and insect resistance, ear, and plant height. Additionally,hybrid performance will differ in different soil types such as lowlevels of organic matter, clay, sand, black, high pH, low pH; or indifferent environments such as wet environments, drought environments,and no tillage conditions. These traits appear to be governed by acomplex genetic system that makes selection and breeding of an inbredline extremely difficult. Even if an inbred in hybrid combination hasexcellent yield (a desired characteristic), it may not be useful becauseit fails to have acceptable parental traits such as seed yield, seedsize, pollen production, good silks, plant height, etc.

To illustrate the difficulty of breeding and developing inbred lines,the following example is given. Two inbreds compared for similarity of29 traits differed significantly for 18 traits between the two lines. If18 simply inherited single gene traits were polymorphic with genefrequencies of 0.5 in the parental lines, and assuming independentsegregation (as would essentially be the case if each trait resided on adifferent chromosome arm), then the specific combination of these traitsas embodied in an inbred would only be expected to become fixed at arate of one in 262,144 possible homozygous genetic combinations.Selection of the specific inbred combination is also influenced by thespecific selection environment on many of these 18 traits which makesthe probability of obtaining this one inbred even more remote. Inaddition, most traits in the corn genome are regrettably not singledominant genes but are multi-genetic with additive gene action notdominant gene action. Thus, the general procedure of producing a nonsegregating F1 generation and self pollinating to produce a F2generation that segregates for traits and selecting progeny with thevisual traits desired does not easily lead to an useful inbred. Greatcare and breeder expertise must be used in selection of breedingmaterial to continue to increase yield and the agronomics of inbreds andresultant commercial hybrids.

Certain regions of the Corn Belt have specific difficulties that otherregions may not have. Thus the hybrids developed from the inbreds haveto have traits that overcome or at least minimize these regional growingproblems. Examples of these problems include in the eastern corn beltGray Leaf Spot, in the north cool temperatures during seedlingemergence, in the Nebraska region CLN (Corn Lethal Necrosis) and in thewest soil that has excessively high pH levels. The industry oftentargets inbreds that address these issues specifically forming nicheproducts. However, the aim of most large seed producers is to provide anumber of traits to each inbred so that the corresponding hybrid can beuseful in broader regions of the Corn Belt. The new biotechnologytechniques such as Microsatellites, RFLPs, RAPDs and the like haveprovided breeders with additional tools to accomplish these goals.

The inbred has been produced through a dihaploid system or isself-pollinated for a sufficient number of generations to give inbreduniformity. During plant selection in each generation, the uniformity ofplant type was selected to ensure homozygosity and phenotypic stability.The line has been increased in isolated farmland environments with dataon uniformity and agronomic traits being observed to assure uniformityand stability. No variant traits have been observed or are expected inNPFF6228.

The best method of producing the invention is by planting the seed ofNPFF6228 which is substantially homozygous and self-pollinating or sibpollinating the resultant plant in an isolated environment, andharvesting the resultant seed.

In the standard CMS system there are three different maize linesrequired to make the hybrid. First, there is a cytoplasmic male-sterileline usually carrying the CMS or some other form of male sterility. Thisline will be the seed producing parent line. Second, there must be afertile inbred line that is the same or isogenic with the seed producinginbred parent but lacking the trait of male sterility. This is amaintainer line needed to make new inbred seed of the seed producingmale sterile parent. Third there is a different inbred which is fertile,has normal cytoplasm and carries a fertility restoring gene. This lineis called the restorer line in the CMS system. The CMS cytoplasm isinherited from the maternal parent (or the seed producing plant);therefore for the hybrid seed produced on such plant to be fertile thepollen used to fertilize this plant must carry the restorer gene. Thepositive aspect of this is that it allows hybrid seed to be producedwithout the need for detasseling the seed parent. However, this systemdoes require breeding of all three types of lines: 1) male sterile-tocarry the CMS, 2) the maintainer line; and, 3) the line carrying thefertility restorer gene.

In some instances, sterile hybrids are produced and the pollen necessaryfor the formation of grain on these hybrids is supplied by interplantingof fertile inbreds in the field with the sterile hybrids.

A number of different inventions exist which are designed to avoiddetasseling in maize hybrid production. Some examples are switchablemale sterility, lethal genes in the pollen or anther, inducible malesterility, male sterility genes with chemical restorers, sterility geneslinked with a parent. U.S. Pat. No. 6,025,546, relates to the use oftapetum-specific promoters and the barnase gene. U.S. Pat. No. 6,627,799relates to modifying stamen cells to provide male sterility. Therefore,one aspect of the current invention concerns the present inventioncomprising one or more gene(s) capable of restoring male fertility tomale-sterile maize inbreds or hybrids.

This invention also is directed to methods for producing a corn plant bycrossing a first parent corn plant with a second parent corn plantwherein the first or second parent corn plant is an inbred corn plantfrom the line NPFF6228. Further, both first and second parent cornplants can come from the inbred corn line NPFF6228 which produces a selfof the inbred invention. The present invention can be employed in avariety of breeding methods which can be selected depending on the modeof reproduction, the trait, and the condition of the germplasm. Thus,any breeding methods using the inbred corn line NPFF6228 are part ofthis invention: selfing, backcrosses, hybrid production, and crosses topopulations, and haploid by such old and known methods of using KWSinducers lines, Krasnador inducers, stock six material that induceshaploids and anther culturing and the like.

The present invention may be useful as a male-sterile plant. Sterilitycan be produced by pulling or cutting tassels from the plant,detasseling, use of gametocides, or use of genetic material to renderthe plant sterile using a CMS type of genetic control or a nucleargenetic sterility. Male sterility is employed in a hybrid production byeliminating the pollen shed from the seed producing parent. The seedproducing parent is grown in isolation from other pollen sources exceptfor the pollen source which is the male fertile inbred, which serves asthe male parent in the hybrid. To facilitate pollination of the seedproducing (female) parent, the male fertile inbreds are planted mostoften in rows near the male sterile (female) inbred.

Methods for genetic male sterility are disclosed in EPO 89/3010153.8, WO90/08828, U.S. Pat. Nos. 4,654,465, 4,727,219, 3,861,709, 5,432,068 and3,710,511. Gametocides, some of which are taught in U.S. Pat. No.4,735,649 (incorporated by reference) can be employed to make the plantmale sterile. Gametocides including but not limited to glyphosate andits derivatives are chemicals or substances that negatively affect thepollen or at least the fertility of the pollen and provide malesterility to the seed producing parent.

Hybrid production employing any form of male sterility includingmechanical emasculation tends to have a small occurrence of selfpollinated female inbred seeds along with the intended F1 hybrid seeds.Great measures are taken to avoid the inbred seed production in a hybridseed production field; but inbred seed unfortunately does occur in F1seed production.

To detect inbred seed in a sample of putative hybrid seed the seeds canbe tested with molecular markers, but another method is to plant theseed. The seed planting process is an inbred capture process whichisolates inbred seed from hybrid F1 seed sources. This process forproducing selected inbred seed comprises planting a group of seedcomprising seed from a hybrid production, some of this seed may be seedof the hybrid parents. The inbred plants tend to be readily identifiablefrom the hybrid plants, the inbreds have a stunted appearance, i.e.shorter plant, smaller ear. Self pollination of the stunted plants grownfrom these identified inbred plants produces the female inbred seed orthe hybrid. The resultant plants are observed for size or they can betested by markers to identify any inbred plants. The identified inbredplants are selected and self-pollinated to form the inbred seed.

A number of well known methods can be employed to identify the genotypeof maize. The ability to understand the genotype of the presentinvention increases as the technology moves toward better markers foridentifying different components within the maize genetic material. Oneof the oldest methods is the use of isozymes which provides ageneralized footprint of the material. Other markers adapted to providea higher definition profile include Restriction Fragment LengthPolymorphisms (RFLPs), Amplified Fragment Length Polymorphisms (AFLPs),Random Amplified Polymorphic DNAs (RAPDs), Polymerase Chain Reaction(there are different types of primers or probes) (PCR), Microsattelites(SSRs), and Single Nucleotide Polymorphisms (SNPs), sequence selectionmarkers just to list a few. The use of these marker techniques forgathering genotype information from seeds and plants is well understoodin the industry. The methods for using these techniques can be found incollege textbooks such as Breeding Field Crops, Milton et. al. IowaState University Press.

The marker profile of the inbred of this invention should be close tohomozygous for alleles. A marker profile produced with any of the locusidentifying systems known in the industry will identify a particularallele at a particular loci. A F1 hybrid made from the inbred of thisinvention will comprise a marker profile of the sum of both the profilesof its inbred parents. At each locus the allele for the presentinvention and the allele for the other inbred parent should be present.Thus the profile of the present invention will permit identification ofhybrids as containing the inbred parent of the present invention. Toidentify the female portion of any hybrid the hybrid seed material fromthe pericarp which is maternally inherited is employed in a markertechnique. The resultant profile is of the maternal parent. Thecomparison of this maternal profile with the hybrid profile will allowidentification of the paternal profile. The present invention includes amaize cell that is part of an inbred or hybrid plant which includes itsseed or plant part that has the marker profile of alleles of the presentinvention.

Marker systems are not just useful for identification of the presentinvention; they are also useful for breeding and trait conversiontechniques. Polymorphisms in maize permit the use of markers for linkageanalysis. If SSR are employed with flanking primers, the marker profilecan be developed with PCR and Southern Blots can often be eliminated.Use of flanking markers, PCR and amplification to genotype maize maturedof the material is well known by the industry. Primers for SSR markersand maize genome mapping information are publicly available through thehelp of the USDA at Maize GDB on the web.

Marker profiles of this invention can be employed to identifyessentially derived varieties or progeny developed with the inbred inits ancestry. This inbred may have progeny identified by having amolecular marker profile with genetic contribution of the present inbredinvention, as measured by either percent identity or percent similarity.

The present invention may have a new locus or trait introgressed throughdirect transformation, breeding methods including but not limited tobackcrossing or marker assisted breeding. A backcross conversion orlocus conversion both refer to a product of a backcrossing program.

The use of the present inbred as a recurrent parent in a breedingprogram it is often referred to as backcrossing. Backcrossing is oftenemployed to introgression a desired trait or trait(s), either transgenicor nontransgenic, into the recurrent parent. A plant with the trait orthe desired locus is crossed into recurrent maize parent usually in oneor more backcrosses. If markers are employed to assist in selection ofprogeny that have the desired trait and recurrent parent backroundgenectics, then the number of backcrosses needed to recover therecurrent parent with the desired trait or locus can be relatively fewtwo or three. However, 3, 4, 5 or more backcrosses are often required toproduce the desired inbred with the gene or loci conversion in place.The number of backcrosses needed for a trait introgression is oftenlinked to the genetics of the line carrying the trait and the recurrentparent and the genetics of the trait. Multigenic traits, recessivealleles, unlinked traits play a role in the number of backcrosses thatmay be necessary to achieve the desired backcross conversion of theinbred.

In a book written by Hallauer entitled Corn and Corn Improvement,Sprague and Dudley, 3rd Ed. 1998 the basics of maize crossing techniquesalong with a number of other corn breeding methods such as recurrent,bulk or mass selection, pedigree breeding, open pollination breeding,marker assisted selection, double haploids development and selectionbreeding are taught. The ordinary corn breeder understands thesebreeding systems and how to apply such techniques to the presentinvention. Therefore, repetition of how to perform these breedingmethods is not listed within this application.

Dominant, single gene traits or traits with obvious phenotypic changesare particularly well managed in backcrossing programs. Prior totransformation and prior to markers, backcrossing was employed since the1950's to breed in identified maize traits.

The backcrossing program is more complicated when the trait is arecessive gene. To determine the presence of the recessive gene requiresthe use of some testing to determine if the trait I has beentransferred. Use of markers to detect the gene reduces the complexity oftrait identification in the progeny. A marker that is a SNP, specificfor the trait, can increase the efficiency and speed of tracking arecessive trait within a backcrossing program. Backcrossing of recessivetraits has allowed known mutation traits to be moved into more elitegermplasm. Mutations can be induced in germplasm by the plant breeder.Mutations can also result from plant or seed or pollen exposure totemperature alterations, culturing, radiation in various forms, chemicalmutagens like EMS and others. Some of the mutant genes which have beenidentified and introgressed into elite maize include the genotypes: waxy(wx), amylose extender (ae), dull (du), horny (h), shrunken (sh),brittle (bt), floury (fl), opaque (o), and sugary (su). Nomenclature formutant genes is based on the effect these mutant genes have on thephysical appearance and phenotype of the kernel. There are mutant geneswhich produce starch with markedly different functional properties eventhough the phenotypes of the seed and plant remain the same. Mutantsubspecies have generally been given a number after the named genotype,for example, sugary-1 (su1), sugary-2 (su2); shrunken 1 (sh1) andshrunken 2 (sh2). Traits such as Ht, waxy, brown mid-rib, amaylose,amlyose brown mid-rib, amylose extender (ae), opaque, dull, imazethapyrtolerant (IT or IR-designations for two different imazethapyr resistantgenes), sterility, fertility, phytic acid, NLB, SLB, and the like haveall been introgressed into elite inbreds through breeding programs. Thelast backcross generation is usually selfed if necessary to recover theinbred of interest with the introgressed trait.

All plants and plant cells produced using inbred corn line NPFF6228 arewithin the scope of this invention. The invention encompasses the inbredcorn line used in crosses with other, different, corn inbreds to produce(F1) corn hybrid seeds and hybrid plants and the grain produced on thehybrid plant. This invention includes plant and plant cells, which upongrowth and differentiation produce corn plants having the physiologicaland morphological characteristics of the inbred line NPFF6228.

This invention also includes transforming of introgressed transgenicgenes, or specific locus into the present invention. The prior art hasan extended list of transgenes, and of specific locus that carrydesirable traits. The transgenes that can be introgressed include butare not limited to insect resistant genes such as Corn Rootworm gene(s)in the event DAS-59122-7, Mir603 Modified Cry3A event, MON 89034, MON88017 Bacillus thuringiensis (Cry genes) Cry34/35Ab1, Cry1A.105, POCry1F, Cry2Ab2, Cry1A, Cry1AB, Cry1Ac Cry3Bb1, or herbicide resistantgenes such as Pat gene or Bar gene, EPSP, the altered protoporphyrinogenoxidase (protox enzyme) U.S. Pat. Nos. 5,767,373, 6,282,837, WO01/12825, or disease resistant genes such as the Mosaic virus resistantgene, etc., or trait altering genes such as lignin genes, floweringgenes, oil modifying genes, senescence genes and the like.

The present invention also encompasses the addition of traits that focuson products or by products of the corn plant such as the sugars, oils,protein, ethanol, biomass and the like. The present invention caninclude a trait that forms an altered carbohydrate or altered starch. Analtered carbohydrate or altered starch can be formed by an introgressedgene(s) that affect the synthase, branching enzymes, pullanases,debranching enzymes, isoamylases, alpha amylases, beta amylases, AGP,ADP and other enzymes which effect the amylose, and or amylopectin ratioor content or the branching pattern of starch. The fatty acid modifyinggenes if introgressed into the present invention can also affect starchcontent. Additionally, introgressed genes that are associated with oreffect the starch and carbohydrates can be adapted so that the gene orits enzyme does not necessarily alter the form or formation of thestarch or carbohydrate of the seed or plant; instead the introgressedgene or its RNA, polypeptide, protein or enzyme adapted to degrade,alter, or otherwise change the formed starch or carbohydrate. Examplesof this technology are shown in U.S. Pat. Nos. 7,033,627, 5,714,474,5,543,570, 5,705,375, 7,102,057, which are incorporated by reference. Anexample of use of an alpha amylase adapted in this manner in maize isshown in U.S. Pat. No. 7,407,677 which is also incorporated byreference.

The methods and techniques for inserting, or producing and/oridentifying a mutation or making or reshuffling a transgene andintrogressing the trait or gene into the present invention throughbreeding, transformation, mutating and the like are well known andunderstood by those of ordinary skill in the art.

Various techniques for breeding, moving or altering genetic materialwithin or into the present invention (whether it is an inbred or inhybrid combination) are also known to those skilled in the art. Thesetechniques to list only a few are anther culturing, haploid/doublehaploid production, (stock six, which is a breeding/selection methodusing color markers and is a method that has been in use for forty yearsand is well known to those with skill in the art), transformation,irradiation to produce mutations, chemical or biological mutation agentsand a host of other methods are within the scope of the invention. Allparts of the NPFF6228 plant including its plant cells produced using theinbred corn line are within the scope of this invention. The termtransgenic plant refers to plants having genetic sequences, which areintroduced into the genome of a plant by a transformation method and theprogeny thereof. Transformation methods are means for integrating newgenetic coding sequences into the plant's genome by the incorporation ofthese sequences into a plant through man's assistance, but not bybreeding practices. The transgene once introduced into plant materialand integrated stably can be moved into other germplasm by standardbreeding practices.

The recombinant DNA molecules of the invention can be introduced intothe plant cell in a number of art-recognized ways. Suitable methods oftransforming plant cells include microinjection (Crossway et al.,BioTechniques 4:320-334 (1986)), electroporation (Riggs et al, Proc.Natl. Acad. Sci. USA 83:5602-5606 (1986)), agrobacterium mediatedtransformation (Hinchee et al., Biotechnology 6:915-921 (1988)), directgene transfer (Paszkowski et al., EMBO J. 3:2717-2722 (1984)), ballisticparticle acceleration using devices available from Agracetus, Inc.,Madison, Wis. and Dupont, Inc., Wilmington, Del. (see, for example,Sanford et al., U.S. Pat. No. 4,945,050; and McCabe et al.,Biotechnology 6:923-926 (1988)), protoplast transformation/regenerationmethods (see U.S. Pat. No. 5,350,689 issued Sep. 27, 1994 to Ciba-GeigyCorp.), Whiskers technology (See U.S. Pat. numbers 5,464,765 and5,302,523) and pollen transformation (see U.S. Pat. No. 5,629,183). Alsosee, Weissinger et al., Annual Rev. Genet. 22:421-477 (1988); Sanford etal., Particulate Science and Technology 5:27-37 (1987)(onion); Christouet al., Plant Physiol. 87:671-674 (1988) (soybean); McCabe et al.,Bio/Technology 6:923-926 (1988) (soybean); Datta et al., Bio/Technology8:736-740 (1990) (rice); Klein et al., Proc. Natl. Acad. Sci. USA,85:4305-4309 (1988) (maize); Klein et al., Bio/Technology 6:559-563(1988) (maize); Klein et al., Plant Physiol. 91:440-444 (1988) (maize);Fromm et al., Bio/Technology 8:833-839 (1990); Gordon-Kamm et al., PlantCell 2:603-618 (1990) (maize); and U.S. Pat. Nos. 5,591,616 and5,679,558 (Rice).

Vectors can include such items as: leader sequences, transitpolypeptides, promoters, terminators, genes, introns, marker genes, etc.The structures of the gene orientations can be sense, antisense, partialantisense, or partial sense: multiple gene copies can be used. Thetransgenic gene can come from various non-plant genes (such as;bacteria, yeast, animals, and viruses) along with being from plants.

The DNA is then transformed into the plant. A transgene introgressedinto this invention typically comprises a nucleotide sequence whoseexpression is responsible or contributes to the trait under the controlof a promoter appropriate for the expression of the nucleotide sequenceat the desired time in the desired tissue or part of the plant.Constitutive or inducible promoters are used. The transgene may alsocomprise other regulatory elements such as for example translationenhancers or termination signals. In an embodiment, the nucleotidesequence is the coding sequence of a gene and is transcribed andtranslated into a protein. In another embodiment, the nucleotidesequence encodes an antisense RNA, a sense RNA that is not translated oronly partially translated, a t-RNA, a r-RNA or a sn-RNA.

Where more than one trait is introgressed into this invention, it isthat the specific genes are all located at the same genomic locus in thedonor, non-recurrent parent, preferably, in the case of transgenes, aspart of a single DNA construct integrated into the donor's genome.Alternatively, if the genes are located at different genomic loci in thedonor, non-recurrent parent, backcrossing allows to recover all of themorphological and physiological characteristics of the invention inaddition to the multiple genes in the resulting maize inbred line.

In an embodiment, a transgene whose expression results or contributes toa desired trait to be transferred to the present invention comprises avirus resistance trait such as, for example, a MDMV strain B coatprotein gene whose expression confers resistance to mixed infections ofmaize dwarf mosaic virus and maize chlorotic mottle virus in transgenicmaize plants (Murry et al. Biotechnology (1993) 11:1559 64). In anotherembodiment, a transgene comprises a gene encoding an insecticidalprotein, such as, for example, a crystal protein of Bacillusthuringiensis or a vegetative insecticidal protein from Bacillus cereus,such as VIP3 (see for example, Estruch et al. Nat Biotechnol (1997)15:137 41). Also see, U.S. Pat. Nos. 5,877,012, 6,291,156; 6,107,2796,291,156 and 6,429,360. In another embodiment, an insecticidal geneintroduced into present invention is a Cry1Ab gene or a portion thereof,for example, introgressed into present invention from a maize linecomprising a Bt-11 event as described in U.S. Pat. No. 6,114,608, whichis incorporated herein by reference, or from a maize line comprising a176 event as described in Koziel et al. (1993) Biotechnology 11: 194200. In yet another embodiment, a transgene introgressed into presentinvention comprises a herbicide tolerance gene, for example, that isresistant to dicamba or a tolerance gene which provides of an alteredacetohydroxyacid synthase (AHAS) enzyme confers upon plants tolerance tovarious imidazolinone or sulfonamide herbicides (U.S. Pat. No.4,761,373). In another embodiment, a non-transgenic trait conferringtolerance to imidazolinones is introgressed into present invention (e.g.a “IT” or “IR” trait). U.S. Pat. No. 4,975,374, incorporated herein byreference, relates to plant cells and plants containing a gene encodinga mutant glutamine synthetase (GS) resistant to inhibition by herbicidesthat are known to inhibit GS, e.g. phosphinothricin and methioninesulfoximine. Also, expression of a Streptomyces bar gene encoding aphosphinothricin acetyl transferase in maize plants results in toleranceto the herbicide phosphinothricin or glufosinate (U.S. Pat. No.5,489,520). U.S. Pat. No. 5,013,659, which is incorporated herein byreference, is directed to plants that express a mutant acetolactatesynthase (ALS) that renders the plants resistant to inhibition bysulfonylurea herbicides. U.S. Pat. No. 5,162,602 discloses plantstolerant to inhibition by cyclohexanedione and aryloxyphenoxypropanoicacid herbicides. The tolerance is conferred by an altered acetylcoenzyme A carboxylase (ACCase). U.S. Pat. No. 5,554,798 disclosestransgenic glyphosate tolerant maize plants, which tolerance isconferred by an altered 5-enolpyruvyl-3-phosphoshikimate (EPSP) synthasegene. U.S. Pat. No. 5,804,425 discloses transgenic glyphosate tolerantmaize plants, which tolerance is conferred by an EPSP synthase genederived from Agrobacterium tumefaciens CP-4 strain. Also, tolerance to aprotoporphyrinogen oxidase inhibitor is achieved by expression of atolerant protoporphyrinogen oxidase enzyme in plants (U.S. Pat. No.5,767,373). Another trait transferable to the present invention confersa safening effect or additional tolerance to an inhibitor of the enzymehydroxyphenylpyruvate dioxygenase (HPPD) and transgenes conferring suchtrait are, for example, described in WO 9638567, WO 9802562, WO 9923886,WO 9925842, WO 9749816, WO 9804685 and WO 9904021. All issued patentsreferred to herein are, in their entirety, expressly incorporated hereinby reference.

In an embodiment, a transgene transferred to present invention comprisesa gene conferring tolerance to a herbicide and at least anothernucleotide sequence encoding another trait, such as for example, aninsecticidal protein. Such combination of single gene traits is, forexample, a Cry1Ab gene and a bar gene. The introgression of a Bt11 eventinto a maize line, such as present invention, by backcrossing isexemplified in U.S. Pat. No. 6,114,608, and the present invention isdirected to methods of introgressing a Bt11 event into present inventionand to progeny thereof using for example the markers described in U.S.Pat. No. 6,114,608.

By way of example only, specific events (followed by their APHISpetition numbers) that can be introgressed into maize plants bybackcross breeding techniques include the glyphosate tolerant event GA21(97-09901p) or the glyphosate tolerant event NK603 (00-011-01p), theglyphosate tolerant/Lepidopteran insect resistant event MON 802(96-31701p) Mon810, Lepidopteran insect resistant event DBT418(96-29101p), male sterile event MS3 (95-22801p), Lepidopteran insectresistant event Bt11 (95-19501p), phosphinothricin tolerant event B16(95-14501p), Lepidopteran insect resistant event MON 80100 (95-09301p)and MON 863 (01-137-01p), phosphinothricin tolerant events T14, T25(94-35701p), Lepidopteran insect resistant event 176 (94-31901p),Western corn rootworm (04-362-01p), the phosphinothricin tolerant andLepidopteran insect resistant event CBH-351 (92-265-01p), and thetransgenic corn event designated 3272 taught in US applicationpublication 20060230473 (hereby incorporated by reference).

A further subject of the present invention is the plants which comprisetransformed cells, in particular the plants regenerated from transformedcells. Regeneration is effected by any suitable process, which dependson the nature of the species as described, for example, in thereferences hereinabove. Patents and patent applications which are citedin particular for the processes for transforming plant cells andregenerating plants are the following: U.S. Pat. Nos. 4,459,355,4,536,475, 5,464,763, 5,177,010, 5,187,073, EP 267,159, EP 604 662, EP672 752, U.S. Pat. Nos. 4,945,050, 5,036,006, 5,100,792, 5,371,014,5,478,744, 5,179,022, 5,565,346, 5,484,956, 5,508,468, 5,538,877,5,554,798, 5,489,520, 5,510,318, 5,204,253, 5,405,765, EP 442 174, EP486 233, EP 486 234, EP 539 563, EP 674 725, WO 91/02071 and WO95/06128.

The use of pollen, cotyledons, zygotic embryos, meristems and ovum asthe target tissue can eliminate the need for extensive tissue culturework. Generally, cells derived from meristematic tissue are useful. Themethod of transformation of meristematic cells of cereal is taught inthe PCT application WO96/04392. Any number of various cell lines,tissues, calli and plant parts can and have been transformed by thosehaving knowledge in the art. Methods of preparing callus or protoplastsfrom various plants are well known in the art and specific methods aredetailed in patents and references used by those skilled in the art.Cultures can be initiated from most of the above-identified tissue. Theonly true requirement of the transforming plant material is that it canultimately be used to form a transformed plant.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322 332 reflectsthat 97% of the plants cultured that produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus that produced plants. In a further studyin 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988), 7:262265 reports several media additions that enhance regenerability ofcallus of two inbred lines. Other published reports also indicated that“nontraditional” tissues are capable of producing somatic embryogenesisand plant regeneration. K. P. Rao, et al., Maize Genetics CooperationNewsletter, 60:64 65 (1986), refers to somatic embryogenesis from glumecallus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345 347(1987) indicates somatic embryogenesis from the tissue cultures of maizeleaf segments. Thus, it is clear from the literature that the state ofthe art is such that these methods of obtaining plants are, and were,“conventional” in the sense that they are routinely used and have a veryhigh rate of success.

Tissue culture procedures of maize are described in Green and Rhodes,“Plant Regeneration in Tissue Culture of Maize,” Maize for BiologicalResearch (Plant Molecular Biology Association, Charlottesville, Va.1982, at 367 372) and in Duncan, et al., “The Production of CallusCapable of Plant Regeneration from Immature Embryos of Numerous Zea maysGenotypes,” 165 Planta 322 332 (1985). Thus, another aspect of thisinvention is to provide cells that upon growth and differentiationproduce maize plants having the physiological and morphologicalcharacteristics of the present invention.

Maize is used as human food, livestock feed, and as raw material inindustry. Sweet corn kernels having a relative moisture of approximately72% are consumed by humans and may be processed by canning or freezing.The food uses of maize, in addition to human consumption of maizekernels, include both products of dry- and wet-milling industries. Theprincipal products of maize dry milling are grits, meal and flour. Themaize wet-milling industry can provide maize starch, maize syrups, anddextrose for food use. Maize oil is recovered from maize germ, which isa by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry. Industrial uses of maize include productionof ethanol, maize starch in the wet-milling industry and maize flour inthe dry-milling industry. The industrial applications of maize starchand flour are based on functional properties, such as viscosity, filmformation, adhesive properties, and ability to suspend particles. Themaize starch and flour have application in the paper and textileindustries. Other industrial uses include applications in adhesives,building materials, foundry binders, laundry starches, explosives,oil-well muds, and other mining applications. Plant parts other than thegrain of maize are also used in industry: for example, stalks and husksare made into paper and wallboard and cobs are used for fuel and to makecharcoal.

The seed of the present invention or of the present invention furthercomprising one or more single gene traits, the plant produced from theinbred seed, the hybrid maize plant produced from the crossing of theinbred, hybrid seed and various parts of the hybrid maize plant, can beutilized for human food, livestock feed, and as a raw material inindustry.

The present invention therefore also discloses an agricultural productcomprising a plant of the present invention or derived from a plant ofthe present invention. The present invention also discloses anindustrial product comprising a plant of the present invention orderived from a plant of the present invention. The present inventionfurther discloses methods of producing an agricultural or industrialproduct comprising planting seeds of the present invention, growingplant from such seeds, harvesting the plants and processing them toobtain an agricultural or industrial product.

A deposit of at least 2500 seeds of this invention will be maintained bySyngenta Seeds Inc. Access to this deposit will be available during thependency of this application to the Commissioner of Patents andTrademarks and persons determined by the Commissioner to be entitledthereto upon request. All restrictions on availability to the public ofsuch material will be removed upon issuance of a granted patent of thisapplication by depositing at least 2500 seeds of this invention at theAmerican Type Culture Collection (ATCC), at 10801 University Boulevard,Manassas, Va. 20110. The ATCC number of the deposit is PTA-13583. Thedate of deposit was Feb. 28, 2013 and the seed was tested on Mar. 19,2013 and found to be viable. The deposit of at least 2500 seeds will befrom inbred seed taken from the deposit maintained by Syngenta SeedsInc. The ATCC deposit will be maintained in that depository, which is apublic depository, for a period of 30 years, or 5 years after the lastrequest, or for the enforceable life of the patent, whichever is longer,and will be replaced if it becomes nonviable during that period.

Additional public information on patent variety protection may beavailable from the PVP Office, a division of the U.S. Government.

Accordingly, the present invention has been described with some degreeof particularity directed to the embodiment of the present invention. Itshould be appreciated, though that the present invention is defined bythe following claims construed in light of the prior art so thatmodifications or changes may be made to the embodiment of the presentinvention without departing from the inventive concepts containedherein.

Variety Description Information

#1 Type: Dent

#2 Region Best Adapted:—Broadly adapted

*MG **Maturity Hybrid Group Range RM***(estimate) 6 108-112 115 *MG =Maturity group **Maturity is the number of days from planting tophysiological maturity (planting to black layer) ***RM = relativematurity#3.

Glume Endosperm Line Anther color SilkColor BraceRootColor CobColorKernelColor Type NPFF6228 Yellow Green Yellow Moderate Red YellowInbred1 Pink Green Green Moderate Pink Yellow Normal#4.

Plant Disease Traits Common Goss' Line Carbonum Rust Eyespot Wilt GLSNCLB SCLB NPFF6228 MS MR MS R MR Inbred1 R MS MR R MS R MR

The data provided above is often a color. The Munsell code is areference book of color, which is known and used in the industry and bypersons with ordinary skill in the art of plant breeding. The purity andhomozygosity of inbred NPFF6228 is constantly being tracked usingisozyme genotypes. Isozyme data can be generated for inbred corn lineNPFF6228 according to procedures known and published in the art.

Isozyme Genotypes for NPFF6228

Isozyme data were generated for inbred corn line NPFF6228 according toprocedures known and published in the art. The data in theElectrophoresis Table gives the electrophoresis data on NPFF6228.

ELECTROPHORESIS RESULTS FOR NPFF6228 Line PGM1 PGM2 PGD1 PGD2 IDH1 IDH2MDH1 MDH2 MDH3 MDH4 MDH5 NPFF6228 9 3 2 2.8 4 4 6 3 16 12 12 Inbred1 9 43.8 5 4 4 6 3 16 12 12 Line MDH6 ACP1 ACP4 GLU PHI CAT3 DIA1 GOT1 GOT2GOT3 ADH NPFF6228 Mm 2 2 0 4 0 0 0 0 0 4 Inbred1 Mm 2 2 . 4 0 0 0 0 0 0

The Paired Inbred Comparison Data Table A show a comparison betweenNPFF6228 and comparable inbreds.

THE PAIRED INBRED COMPARISON DATA TABLE A Inbred Yield Stand HeatUnitsto P50 HeatUnits to S50 Plant Height Ear Height NPFF6228 120.4 34611.11382.9 1403.1 74.4 36.9 Inbred1 122.4 33708.3 1422.8 1451.1 76.1 38.1Diff 6.7 458.3 39.9 48 2.7 2.5 # Expts 6 6 18 17 5 5 Prob 0.377 0.4540.001*** 0.000*** 0.128 0.158 % Large % Large % Med. % Med. % Small %Small Shed Pollen Inbred Rounds Flats Rounds Flats Rounds Flats DurationCount NPFF6228 11.4 1.6 1.6 1.6 26.6 52.1 Inbred1 28.5 6.2 0.4 0.6 1543.6 165.7 725037 Diff # Expts Prob *.05 < Prob <= .10 **.01 < Prob <=.05 ***.00 < Prob <= .01

The General Combining Ability Table shows the GCA (General CombiningAbility) estimates of NPFF6228 compared with the GCA estimates of theother inbreds. The estimates show the general combining ability isweighted by the number of experiment/location combinations in which thespecific hybrid combination occurs. The interpretation of the data forall traits is that a positive comparison is a practical advantage. Anegative comparison is a practical disadvantage. The general combiningability of an inbred is clearly evidenced by the results of the generalcombining ability estimates. This data compares the inbred parent in anumber of hybrid combinations to a group of “checks”. The check data isfrom our company's and other companies' hybrids which are commercialproducts and pre-commercial hybrids, which were grown in the same setsand locations.

GCA TABLE % Late % Early % Stalk % Push Root Root % Dropped Final Line NYield Moisture TestWeight Lodging Test Lodging Lodging Ears StandNPFF6228 138 5.8 −0.81 −0.41 −0.29 −0.97 2.58 2.58 0.01 −0.46 XR = 1385.8 −0.81 −0.41 −0.29 −0.97 2.58 2.58 0.01 −0.46 XH = 1 5.8 −0.81 −0.41−0.29 −0.97 2.58 2.58 0.01 −0.46 XT = 1 5.8 −0.81 −0.41 −0.29 −0.97 2.582.58 0.01 −0.46 Stay % Green Emergence Vigor Heatunits Heatunits EarPlant Line Green % Snap % Barren Rating Rating to S50 to P50 HeightHeight NPFF6228 4.51 −1.36 −0.52 −0.19 0.09 −25.75 −25.47 2 −3.79 XR =4.51 −1.36 −0.52 −0.19 0.09 −25.75 −25.47 2 −3.79 XH = 4.51 −1.36 −0.52−0.19 0.09 −25.75 −25.47 2 −3.79 XT = 4.51 −1.36 −0.52 −0.19 0.09 −25.75−25.47 2 −3.79

The Paired Hybrid Comparison Data Table A through B shows the inbredNPFF6228 in hybrid combination, as Hybrid 1, in comparison with anotherhybrid, which is adapted for the same region of the Corn Belt.

PAIRED HYBRID COMPARISON DATA TABLE A Hybrid Yield Moist TWT PCTERLPCTSL PCTPUSH PLTLRL PCTDE Hybrid1 w/ NPFF62282 211.7 23.4 53.8 4.7 425.9 1.9 0 Hybrid2 209.6 23 53.9 13.6 7.8 23.3 5.9 0 # Expts 160 160 6411 70 15 41 11 Diff 2.1 0.4 0.1 8.9 3.9 2.5 4 0 Prob 0.23 0.001*** 0.9110.113 0.063* 0.693 0.019** Hybrid Stand PCTSG PCTGS PctBarren EmergeVigor HUS50 Hybrid1 w/ NPFF6228 203.9 11.7 0.6 3.3 3.7 1326 Hybrid2206.5 8.7 5.4 3.4 3.7 1338 # Expts 167 3 18 31 41 15 Diff 2.6 3 4.8 0.10 11.2 Prob 0.029** 0.483 0.115 0.712 0.923 0.298 Hybrid HUP50 PlthtEarht Hybrid1 w/ NPFF6228 1319 261.6 121.2 Hybrid2 1339 273.4 125.3 #Expts 13 26 26 Diff 20 11.7 4.1 Prob 0.103 0.000*** 0.055* *.05 < Prob<= .10 **.01 < Prob <= .05 ***.00 < Prob <= .01

PAIRED HYBRID COMPARISON DATA TABLE B Hybrid Yield Moist TWT PCTERLPCTSL PCTPUSH PLTLRL PCTDE Hybrid1 w/ NPFF6228 214.1 23.6 53.5 5.2 0.626.3 0.6 0 Hybrid3 211.3 23.8 53.4 15 0.4 7.4 7 0 # Expts 59 65 31 5 267 13 1 Diff 2.9 0.2 0.1 9.8 0.2 18.9 6.4 0 Prob 0.258 0.284 0.782 0.2530.305 0.054* 0.116 Hybrid Stand PCTSG PCTGS PctBarren Emerge Vigor HUS50Hybrid1 w/ NPFF6228 238.7 0.6 3.4 3.6 1298 Hybrid3 237.6 1.3 3.5 3.21306 # Expts 67 6 14 17 5 Diff 1.1 0.7 0.1 0.4 8.2 Prob 0.63 0.335 0.5460.111 0.431 Hybrid HUP50 Pltht Earht Hybrid1 w/ NPFF6228 1296 259.4122.3 Hybrid3 1306 270.3 126.1 # Expts 5 11 11 Diff 10.6 10.9 3.8 Prob0.311 0.021** 0.409

The Yield by Environment Response Table shows the yield response ofHybrid 1 w/NPFF6228 as a parent in comparison with two other hybrids andthe plants in the environment around it at the same location.

Yield By Environment Response Table Research Plots Environment YieldHybrid Error # Plots 75 100 125 150 175 200 Hybrid1 w/ 19.9 138 94 118142 165 189 213 NPFF6228 Hybrid2 22.3 1164 98 122 146 170 193 217Research Plots Environment Yield Hybrid Error # Plots 75 100 125 150 175200 Hybrid1 w/ 19.9 138 94 118 142 165 189 213 NPFF6228 Hybrid3 18.4 12081 107 134 160 186 212 Strip Tests Environment Yield Hybrid Error #Strips 75 100 125 150 175 200 Hybrid1 w/ 1 66 77 104 130 156 182 208NPFF6228 Hybrid2 1.2 284 77 103 128 154 180 205 Strip Tests EnvironmentYield Hybrid Error # Strips 75 100 125 150 175 200 Hybrid1 w/ 1 66 77104 130 156 182 208 NPFF6228 Hybrid3 1.5 97 77 103 129 155 180 206

Accordingly, the present invention has been described with some degreeof particularity directed to the embodiment of the present invention. Itshould be appreciated, though that the present invention is defined bythe following claims construed in light of the prior art so thatmodifications or changes may be made to the embodiment of the presentinvention without departing from the inventive concepts containedherein.

I claim:
 1. A seed of the maize variety NPFF6228, representative seed ofsaid variety having been deposited under ATCC Accession NumberPTA-13583.
 2. A maize plant of maize variety NPFF6228, representativeseed of said variety having been deposited under ATCC Accession NumberPTA-13583.
 3. An F1 hybrid maize seed produced by crossing a maize plantvariety NPFF6228 according to claim 2 with itself or a different maizeplant.
 4. A maize plant part of the plant of claim
 2. 5. A maize plantpart according to claim 4 comprising a seed.
 6. A maize plant or itsparts produced by growing the F1 hybrid maize seed of claim
 3. 7. A cellfrom a maize tissue culture of regenerable cells of the plant of claim2.
 8. A method of producing a maize plant variety NPFF6228 with adesired trait into comprising: (a) crossing a NPFF6228 plant accordingto claim 2, with a plant of another maize line that comprises thedesired trait to produce F1 progeny plants, wherein the desired trait isselected from the group consisting of waxy starch, amylase, malesterility, modified carbohydrates, modified corn fiber, modified fattyacids metabolism, modified fatty acids, herbicide resistance, insectresistance, bacterial disease resistance, fungal disease resistance, andviral disease resistance; (b) selecting F1 progeny plants that have thedesired trait to produce selected F1 progeny plants; (c) crossing theselected progeny plants with the NPFF6228 plants to produce backcrossprogeny plants; (d) selecting for backcross progeny plants that have thedesired trait to produce selected desired progeny plants; and (e)repeating steps (c) and (d) at least one more times to produce plantsthat comprise the desired trait and all of the physiological andmorphological characteristics of maize plant variety NPFF6228 when grownin the same environmental conditions.
 9. A maize seed from a derivedmaize variety NPFF6228 produced by the process of claim
 8. 10. A methodof producing a plant byproduct comprising obtaining the plant of claim 6or a part thereof and producing said plant byproduct therefrom.
 11. Aprocess of producing maize seed comprising a transgene encoding anamylase, comprising crossing a first parent maize plant according toclaim 2 with a second parent maize plant with said transgene, andharvesting the resultant seed.
 12. The maize seed according to claim 5further comprising a transgene.
 13. The maize seed of claim 12, whereinthe maize seed is hybrid seed.
 14. A method of producing a second maizeplant comprising introducing a transgene or trait allele conferring adesired trait into the plant of maize variety NPFF6228 according toclaim 2, and wherein said introduction results in the production of saidsecond maize plant.
 15. The method of claim 14 wherein the desired traitis herbicide resistance, selected from a group comprising: glyphosate,sulfonylurea, imidazolinone, dicamba, glufosinate, phenoxypropionicacid, cyclohexanedione, triazine, benzonitrile and bromoxynil.
 16. Thesecond maize plant produced by the method of claim 14, wherein the geneconfers a trait selected from the group consisting of herbicidetolerance; insect tolerance; resistance to bacterial, fungal, nematodeor viral disease; waxy starch; male sterility and restoration of malefertility, modified carbohydrate metabolism and modified fatty acidmetabolism.
 17. A method of producing a maize plant derived from thevariety NPFF6228, the method comprising the steps of (a) growing aprogeny plant produced by crossing the plant of claim 2 with a secondmaize plant; (b) crossing the progeny plant with itself or a differentplant to produce a seed of a progeny plant of a subsequent generation;(c) growing a progeny plant of an earlier generation from said seed andcrossing the progeny plant of a subsequent generation with itself or adifferent plant; and (d) repeating steps (b) and (c) for an additional0-5 generations to produce a maize plant derived from the varietyNPFF6228.
 18. A method of claim 10 wherein the plant byproduct issilage, starch, ethanol, oil, syrup, meal, amylase, or protein.
 19. Amethod for developing a maize derived plant from the plant of claim 2comprising the steps of crossing the plant of claim 2 with at least oneother plant to form a plant population; breeding said plant populationwith plant breeding techniques selected from the group consisting ofrecurrent selection, backcrossing, pedigree breeding, genetic markerenhanced selection, and double haploid breeding, forming breedingprogeny, and selecting maize derived plants from said breeding progeny.